In recent years, a power converter is required to output a large current and also required to reduce its size. When a power converter outputs a large current, heat generated in a power semiconductor device incorporated in a power semiconductor module is increased. Therefore, if heat capacities of the power semiconductor module and the power converter are not increased, the generated heat reaches a heat resistance temperature of the power semiconductor device, and it hinders the size reduction. A double-sided cooling power semiconductor module which can improve a cooling efficiency by cooling a power semiconductor device from double sides and a double-sided cooling power converter using the double-sided cooling power semiconductor module have been developed.
In the double-sided cooling power semiconductor module, double main surfaces of the power semiconductor device are sandwiched by plate-like conductors. Further, surfaces facing the main surfaces of the power semiconductor device and surfaces of the plate-like conductors on the opposite side are cooled by being thermally connected to a cooling medium, and a main circuit is wired by a bus bar assembly connecting a plurality of the double-sized cooling power semiconductor modules.
A power converter is disclosed in PTL 1. In the power converter, a power module is formed by sandwiching, by plate-like lead frames, double main surfaces of a power semiconductor device included in an arm of an inverter circuit. The power module is inserted into a case storing a plurality of the power modules and fixed by being sandwiched by the case. A main circuit wiring is formed by connecting the power modules by a bus bar integrated into the case by an insulating resin.
On the other hand, in a power converter disclosed in PTL 2, a power module is formed by sandwiching, by plate-like lead frames, double main surfaces of a power semiconductor device included in an arm of an inverter circuit. The power module and a cooling water passage are disposed so as to surround a capacitor module to improve a cooling efficiency of the whole of an inverter main circuit.